I had heard of the film, of course. But was not familiar with it. I had always thought it dealt with an escape from an ordinary prison. Just took a look on IMDB and it has 8.4/10 with over 35K votes - that's a pretty strong ranking. Now I'll have to see about recording it next time it's broadcast here; which looks to be in a couple of weeks.
There were also POW camps in the US. The German's had their own 'great escape' from the Papago Park POW camp near Phoenix, Arizona. They had makeshift inflatable boats and headed to the mighty Salt River to float & escape down to Mexico - not realizing that Arizona 'rivers' are just dried up gullies most of the year.